| x | + | ( | x | + | 28 | ) | × | 3 | ÷ | 4 | = | 42 |
| Left side of the equation = | x | + | ( | x | + | 28 | ) | × | 3 4 |
| x | + | ( | x | + | 28 | ) | × | 3 4 | = | 42 |
| Left side of the equation = | x | + | x | × | 3 4 | + | 28 | × | 3 4 |
| = | x | + | x | × | 3 4 | + | 21 |
| = | 7 4 | x | + | 21 |
7 4 | x | + | 21 | = | 42 |
7 4 | x | = | 42 | − | 21 |
7 4 | x | = | 21 |
| x | = | 21 | ÷ | 7 4 |
| = | 21 | × | 4 7 |
| = | 3 | × | 4 |
| x | = | 12 |